Pivot-joint.



PATENTED SEPT. 18, 1906.

C. D. KING.

PIVOT JOINT. APPLICATION FILED DEO. 4. 1905.

CHARLES D. KING, OF BROOKLYN, NEW YORK.

PIVOT-JOINT.

Specification of Letters Patent.

unir 'am ra. en sep.18,19oe.

Application tiled December 4, 1905. Serial No. 290.104.

To all, whom, it may concern.-

Be it known that I, CHARLES D. KING, a citizen of the United States, anda resident of Brooklyn, in the county of Kings and State of New York,have invented certain new and useful Improvements in Pivot-Joints, ofwhich the following is a specification.

This invention relates to pivot-joints 5 and its object is to providejoints of this class which can be more readily adjusted than thoseheretofore made, which will be less liable to breakage, and which willneed a minimum of repairing.

The invention is applicable to a number of articles, but is shownapplied to mathematical instruments, such as Compasses or dividers; butI do not limit myself to this application of the invention. Pivot-jointsas commonly made for such instruments consist of a forked handlecontaining` a pair of screwpivots impinging in depressions in the upperends of the compass-legs, and the pivots are kept from turning by smallset-'screws bearing on the threads of the pivot-screws or by lock-nuts.It is obvious that the set-screws will often ruin the `threads of thepivots, and also they are often broken off and ruin the instruments. Thelock-nuts when used are unsatisfactory and imperfect in their action,frequently working loose, and requiring adjustment at inconvenienttimes.

My invention differs from others of the class named from the fact thatthe pivots and their adjusting means are made as separate members, andby that separation it is possible to positively lock the pivots againstrotative movement relative to their supports when the instrument isopened and closed, and thus to make it impossible to turn theadjusting-screws the smallest fraction of a turn by such action. Thismakes the adjustment very lasting and obviates the need of locking theadjusting screws or screw, (where only one is used,) so thatreadjustment is made by a slight turning. of these screws.

Referring to the drawings, Figure l is an enlarged side elevation,partly in section, on the center line of a compass or divider embodyingmy invention. Fig. 2 is a front elevation of the same. Figs. 3 and 4 arerespectively side elevation and transverse section of the pivots drawnto a still larger scale. elevation and longitudinal section of theadjusting-screws.

Figs. 5 and 6 are respectively front.

The instrument here illustrated has the usual divider-legs a a', formedwith diskshaped upper ends b b and a forked supporting member c, havinga handle c and proj ections c2 c3 to support the pivots d andadjusting-screws c and -Referring to Figs.' 3 and 4, the pivots are seento be formed with conical pivoting-surfaces d, which bear in conicaldepressions a2, formed in the ends of the divider-legs. They also havesquare-ended lugs or elongations d2, adapted to lock against the upperinside face c4 of the pivot-supporting member c, and they have holes d,which fit the pin or elongation of the screw e..

The adjusting-screws e and f are short headless screws of ne pitch,having the usual slots for turning them. The screw c has an elongation@Q smaller in diameter than the threaded portion, which fits the holesd3 in the pivots and also passes freely through holes a3 in thedivider-legs a a and enters the hole f in the screwf when the variousparts are assembled. The hole f extends nearly through the screw f, sothat a small clearance is left between the end of the pin c and the endof the hole when both are in place in the instrument, thus allowing forsuch adjustment as becomes necessary through wear on the pivots.

To assemble the various parts of the instrument, the legs (L a areplaced together, while the pivots d d are placed in the depressions az,the fork c is slipped over them, and the screws e and f are placed intheir respective holes in the fork c, the pin c serving to bring thepivots in line with each other and with the other screwf, after whichthe screws are given their final adjustment to bring the pivots againstthe divider-legs with sufficient pressure to secure easy and accurateworki ng of the instrument. j Adjustment is made afterward as thepivoting-surfaces wear off by turning one or other of the screws a veryslight amount, and they remain positively in j such adjustment, as thereis nothing to give unintentional turning of the adj usting-screws. Forturning the screws a screw-driver is preferred; but they may also beadapted for wrenches of suitable construction.

If desired, the adjusting-screwf may be omitted from the instrument, andin such a modification it would be necessary to have the pin e i'it anunthreaded hole in the proj ection c3 to bring the pivots into properalinement.

IOO

IIC

Various other modifications, may be devised within the scope of myinvention, and I do not limit myself to one particular form.

I claim as my inventionl. A pivot-joint for relatively movable members,comprising a suitable support, pivoting means within said support havingintegral locking means, juncture portions on the relatively movablemembers also disposed within said support and pivotcd by said pivotingmeans, means for holding the pivoting means and the said junctureportions to the support, and means for adjusting said pivoting means andsaid juncture portions in position.

2. A pivot-joint 'for relatively movable members, comprising a suitablesupport, a pivot having integral means for locking it against rotativemovement, juncture portions of relatively movable members connectabletherewith, and means for holding said juncture portions and pivot to thesupport and adjusting them in proper position.

3. A pivot-joint Jfor relatively movable members, comprising a vforkedsupport, pivotal portions of relatively movable members projecting intothe fork thereof, self-locking` pivots on opposite sides of' saidpivotal portions witliin said fork, and means Jfor holding and adjustingsaid pivotal portions and said pivots `in their respective positions inthe support.

4. A pivot compass joint comprising a yoke, self-locking pivots carriedtherein, pivotal portions of compass-legs pivoted by said pivots, andmeans for alining and holding the pivots and pivotal portions of thelegs to the yoke and usting them in position.

5. A pivot compass-joint comprising a forked support, pivots carriedtherein having lugs locking with said support to prevent rotation of thepivots, pivotal portions of compass-legs pivoted by said pivots, screwsfor adjusting said pivots, and a central member for alining the pivotsand the pivotal portions of the legs with the support.

Signed at New York, in the county of New York and State of New York,this 24th day of November, A. D. 1905.

CHARLES D. KING.

l/Vitnesses:

ADoLPi-r F. DrNsE, EDGAR A. FnLLows.

